1. Field of the Invention
This invention relates generally to apparatus for ensuring the closure of a door and more particularly to apparatus for locking a door against forcible entry.
2. Description of the Prior Art
It is desirable to lock a door, which typically provides entrance to a household, against entry by an intruder. To this end, locking mechanisms such as deadbolts have been utilized to discourage unlawful entry. Commercial dead bolts typically include a metal bar and upon activation insert the metal bar into a receiving aperture in a door jamb. The metal bars range in length from 3/4 an inch to 1 and 1/2 inches. While dead bolts do prevent access through the use of plastic cards which are so effective in gaining illegal entry through the common door lock whose locking bar includes a tapered face which can be pushed to an open position by the use of the plastic card, the dead bolt offers little or no protection against "kick-in's". Because the dead bolt has a single point of contact, the application of force such as a stout kick will tear the dead bolt from the door jamb and permit access to a house, a business, and any other establishment where security against unlawful entry is desired. There are, of course, multi-point locking systems. These however are cost prohibitive.
It is therefore an object of the present invention to provide a security locking mechanism for a door which is operable from either side of the door and prevents entry by "kick-in", "prying" or "jimmying".
It is another object of the present invention to provide a security locking mechanism that can be installed in existing doors.
It is still another object of the present invention to provide a security door assembly having a self-contained locking assembly therein adapted for securing the top and adjacent side of a door in locking engagement with adjacent door jamb structure.
It is yet another object of the present invention to secure the locking assembly in either a locked position or an open position.